The present invention relates to a stamping device for use in packaging machines for producing closed content-filled rectangular parallelepipedal containers from a web of packaging material, the stamping device being adapted to impress the web with data such as the preservable period, quality retaining period, time, lot number and production supervision mark.
JP-B-44525/1982, FIG. 3 discloses a conventional stamping device for use in packaging machines for producing closed content-filled rectangular parallelepipedal containers from a web of packaging material. The disclosed stamping device comprises one stamp roller having an interchangeable stamp.
When the data to be impressed is to be altered, the conventional stamping device requires the procedure of suspending the operation of the packaging machine and replacing the stamp by another stamp. The device therefore has the problem the alteration of the data to be impressed diminishes the operating time of the packaging machine.